Peter Hyams' "Capricorn One" arrives on DVD with full helmer commentary and a 17-minute featurette examining how eroding trust in government fuels even lunatic theories.

The 1970s were a great time for conspiracy pics, as evidenced by “The Parallax View,” “The Conversation” and “Three Days of the Condor.” Add Peter Hyams’ “Capricorn One” (1978) to the mix as well, now issued on DVD with full helmer commentary and a 17-minute featurette examining how eroding trust in government fuels even lunatic theories.

Pic’s plot centers on an aborted manned mission to Mars for which rogue NASA personnel concoct an elaborate ruse that includes murdering three astronauts rather than admit failure. Yet unlike some of its darker counterparts, this movie concludes on a relatively affirming note.

For many, the most interesting aspect of “Capricorn” is O.J. Simpson’s appearance as one of the astronauts, along with James Brolin and Sam Waterston. But anyone anticipating a major re-evaluation of the former football star’s acting should lower expectations. He doesn’t even speak until 20 minutes into the film, and when he does, he’s given lines like, “I think I’m gonna throw up.”

Remaining cast is a virtual who’s who of celebrities for that decade, including Elliott Gould as a dogged investigative journalist, Brenda Vaccaro as Brolin’s wife and Telly Savalas as a nutty crop duster. But the pic really belongs to Hal Holbrook, as the NASA exec behind the crazy scheme.

Hyams, who also penned the movie, credits Holbrook and plenty of others in an engaging commentary notable for its clarity, focus and lack of self-absorption. Indeed, his memory is so sharp, one almost doubts his word that this is the first time he’s seen the film since its release.

The featurette “Flights of Fancy: The Politics and Paranoia of ‘Capricorn One'” makes a fine capper. Hyams, who worked for CBS News for seven years before embarking on a filmmaking career, historian Steven Ross and Skeptic magazine editor Michael Shermer suggest that Americans’ distrust of government — which began with Vietnam, reached an apex during the Nixon years and achieved new heights during the present administration — is a major reason crank ideas gain traction. Worth pondering is Ross’ point that technologies such as CGI only increase our chances of being fooled.

The feature itself, however — even annotated by its creator — lacks the legs to compete with more accomplished efforts from a time when Americans could believe the worst about their government rather than not care enough to bother.